With a conventional telescopic ball-point pen, when the pen is not in use, its frontal axial portion and rear axial portion are moved closer together, thereby engageably striking an internal push rod with a sliding tip portion, so that the sliding tip portion is projected to a position to thereby conceal a tip of a ball-point pen refill. When the pen is in use, the frontal axial portion and the rear axial portion are moved away from each other, thereby disengaging the push rod from the sliding tip portion, so that the sliding tip portion is retracted to a position to expose the tip of a ball-point pen refill.
Construction of this type of telescopic ball-point pen requires high-precision machining, with a relatively low yield. Further, the assembly work required tends to be complex and costly.